1. Field of the Invention
The present invention relates to an imaging apparatus that includes a thin-film transistor (TFT) and a conversion element, a method for manufacturing the imaging apparatus, and a radiation imaging system.
2. Description of the Related Art
A technique for manufacturing a liquid crystal panel that employs a TFT is utilized in an area sensor that includes a conversion element that converts light (e.g., visible light) or radiation (e.g., an X ray) into an electric signal.
U.S. Patent No. 2003-0010922 describes an apparatus that includes a first protecting insulation layer on a TFT array, storage capacity electrodes connected to a ground wire on the first protecting insulation layer, a second protecting insulation layer that covers the storage capacity electrodes formed on the first protecting insulation layer, and a pixel electrode connected to a drain electrode of the TFT on the second protecting insulation layer, with at least one portion of the storage capacity electrodes shielding the TFT region. U.S. Patent No. 2002-0056810 describes an apparatus that includes a reading field-effect transistor having a gate for receiving a signal charge generated in the photoelectric conversion element and a source and a drain for reading a signal corresponding to the signal charge accumulated in the gate.
However, in known apparatuses, when a plurality of TFTs is arranged, the number of wirings that cross a signal wiring via a gate insulation layer is increased, thus increasing a parasitic capacitance. This reduces a signal-to-noise (S/N) ratio.